(JTA) — The family of a Jewish woman who sold a valuable painting under duress while fleeing the Nazis can sue a museum in Madrid for its return, a U.S. federal appeals court ruled.

The 9th US Circuit Court of Appeals ruled Monday that the family of Lilly Cassirer may sue the Thyssen-Bornemisza Museum in Madrid for the 1897 painting “Rue Saint-Honoré, Après-midi, Effet de Pluie,” a Paris street scene by Camille Pissarro, which is valued at at least $40 million.

The painting has been on display in the museum since 1992.

In 2005, Cassirer’s grandson Claude sued for restitution of the painting, which his German-born grandmother sold in 1939 to an art dealer for the equivalent of $360 as she was fleeing her homeland from the Nazis. Cassirer’s father-in-law, Julius, had purchased the painting from the painter.

The painting was acquired by Baron Hans Heinrich Thyssen-Bornemisza in 1976 and has been displayed in Madrid since the museum opened in late 1992, after the Baron gave his collection to the Spanish government; he died in 2002. The painting was insured for over $10 million.

Judge John Walter of the Los Angeles District Court of California ruled in June 2015 that that Spanish law applied in the case, and the law did not require the painting’s return since it is not known whether the museum knew it was stolen when it acquired the painting. The ruling came after a decade-long dispute over ownership.

The case has been returned to Walter and the Los Angeles District Court.

Cassirer reportedly did not know that the artwork remained in existence when she accepted a payment for it from the German government in 1958. She did not waive her rights to the art, either.